Salim Arrache has penned a three-and-a-half year contract at Marseille.
The former Strasbourg winger has recently had a spell on the sidelines after suffering a serious knee injury.
Arrache hopes to be able to make his first appearance for l'OM by the end of January.
"I am very happy, I have joined Marseille and for me it is my childhood dream," Arrache told the club's official website.
"I have had six difficult months after my injury, but today I have signed.
"Bouncing back at Marseille, there is nothing better. I am preparing myself to be ready for the end of January."
Elsewhere, Marseille chairman Pape Diouf has played down talk of a move for France defender Lilian Thuram.
L'OM have been linked with the Barcelona stopper in recent days but Diouf has rejected suggestions of a bid.
"The Thuram rumour is unfounded, we don't have the required conditions to be able to sign Thuram," Diouf said.
"But now that the rumour has been told and written, may be it will give some ideas to Thuram and ourselves."
Diouf also rejected any possibility of a departure for Taye Taiwo.
He added: "The tale that sends Taye Taiwo to England is just a rumour."
However, Habib Beye could leave the Stade Velodrome, with Bayer Leverkusen reportedly tracking the defender.
Meanwhile, Marseille are being linked with Monaco playmaker Camel Meriem and FC Copenhagen defender Michael Gravgaard, but any chance of signing Porto's Ricardo Costa appear to have been dashed.
"There is no agreement between the clubs," a Porto spokesman told the club's official website. "Ricardo Costa is indispensable to the team."